Abstract

A large positive magnetoresistance(MR) at room temperature was observed in a GaAs:MnAs granular thin film, in which MnAs nanoclusters were embedded in a GaAs matrix. Current-voltage characteristics and a MReffect of the GaAs:MnAs thin film were measured by a two-point-probe method. The MR ratio of the GaAs:MnAs granular thin film reached more than 600%, when a bias voltage of 110 V was applied to the film.

This work was partially supported by the PRESTO and SORST programs of JST, Grant-in-Aid for Scientific Research, IT Program of RR 2002 from MEXT, and the Toray Science Foundation. One of the authors (M. Y.) is thankful for financial support from the JSPS Research Fellowships for Young Scientists.